1. Field
The present invention relates generally to a semiconductor device and a method of manufacturing the same, and in particular to a three-dimensional semiconductor device and a method of manufacturing the same.
2. Discussion of Related Art
A non-volatile memory device is a memory device in which stored data is retained even after power is removed. Recently, a three-dimensional non-volatile memory device, where memory cells are vertically stacked on a silicon substrate, has been developed in response to the perception that two-dimensional memory devices are pushing the boundaries of device integrity. Memory cells are formed with one layer on a silicon substrate in the two-dimensional memory device.
The three-dimensional non-volatile memory device accesses a desired memory cell by supplying appropriate biases to word lines stacked on the substrate. When the memory device is manufactured, pad portions of respective word lines are defined by patterning a contact region of stacked word lines in a stair configuration, and then connecting contact plugs to the pad portions of the word lines. During manufacture, an etching process is iteratively performed by reducing one mask pattern so as to pattern the stacked word lines in the desired stair configuration. Consequently, the process of manufacturing the memory device is complex and difficult to implement successfully. Since contact region area within the memory device is high, it is difficult to enhance the integrity of the memory device. Specifically, it is difficult to increase memory capacity while retaining high levels of performance and reliability.